NC Data creation method

ABSTRACT

The invention relates to a method of creating NC data for machining the interior of an area. The method includes displaying, on a graphic display unit (106), contours (CNT1, CNT2) inputted in order to specify the area (AR M ), recognizing the area (AR M ), which is designated by a graphic cursor by manipulation of a tablet (108) and painting the interior of the area in a predetermined color, subsequently removing the paint in a linear area (AR 1 ), having a width equivalent to a width of a tool, which connects a machining starting point (P S ) and a machining end point (P E ) designated by the graphic cursor, adopting the machining end point as the next machining starting point, thereafter inputting machining end points in succession, and creating NC data for machining the interior of the area (AR M ) by traversing a finally designated machining starting point and machining end point while moving the tool linearly.

DESCRIPTION

1. Technical Field

This invention relates to a method of creating NC data, and moreparticularly, to an NC data creation method in which the path of a toolfor machining the interior of an area can be inputted while beingperceived visually.

2. Background Art

In the prior art, if a machining method (one-way cutting, two-waycutting, spiral cutting, etc.), cutting direction, cut-in direction,finishing allowance, remaining thickness, spindle speed, cuttingvelocity, tool diameter and the like are inputted in accordance with thesame conversational display, a tool path may be decided and createdbased on an already defined contour irrespective of whether NC data forsubjecting the interior of the contour to surface machining or pocketmachining is for the purpose of rough machining or finishing machining.

This conventional method is advantageous in that NC data for highlyprecise cutting is obtained. When a contour is a complicated one,however, considerable time is required to create the NC data and thetool path includes needless path segments (paths which do not contributeto cutting). Cutting efficiency suffers as a result.

In the case of rough machining, the NC data for cutting need not have ashigh a precision as that for finishing machining. Accordingly, there isa demand for a method through which data required for the creation of NCdata for rough machining may be simply defined in a manner differentfrom that of the conventional method so as to raise machiningefficiency.

An object of the invention is to provide an NC data creation methodthrough which NC data for rough machining of an area can be simplycreated for excellent cutting efficiency.

Another object of the invention is to provide an NC data creation methodthrough which it is possible to recognize at a glance whether portionsremain to be cut or will be cut too much.

DISCLOSURE OF THE INVENTION

An NC data creation method for machining the interior of an areaincludes displaying, on a graphic display unit, contours inputted inorder to specify the area, recognizing the area, which is designated bya graphic cursor by manipulation of a tablet and painting the interiorof the area in a predetermined color, subsequently removing the paint ina linear area, which has a width equivalent to a width of a tool,connecting a machining starting point and a machining end pointdesignated by the graphic cursor, adopting the machining end point asthe next machining starting point, thereafter inputting machining endpoints in succession, and creating NC data for machining the interior ofthe area by traversing a finally designated machining starting point andmachining end point while moving the tool linearly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an automatic programming system to whichthe method of the invention can be applied;

FIG. 2 is a flowchart of processing according to the invention;

FIG. 3 is a view showing the shape of a workpiece and the shape of apart; and

FIG. 4 is a view for describing processing according to the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a block diagram of an automatic programming system to whichthe method of the invention can be applied.

Numeral 101 denotes a ROM storing a loading program and the like, 102 aprocessor which performs automatic programming processing, and 103 aRAM. The RAM 103 stores a system program STPR for NC data creation readin from a floppy FL, the results of processing, etc.

Numeral 104 denotes an NC data memory for storing created NC data, 105 akeyboard, 106 a graphic display unit (CRT), 107 a disk controller, and108 a tablet device having a tablet surface 108a to which a menu table108b is affixed. The tablet is so adapted that a prescribed menu itemcan be selected by a tablet cursor 108c. Further, the arrangement issuch that a graphic cursor GCS on the display screen is moved by movingthe tablet cursor 108c on the tablet surface. The menu table 108b isprovided with various menu items, among which the items "OPTIONALCUTTING" and "END" have a bearing upon the present invention.

FIG. 2 is a flowchart of processing according to the present invention,FIG. 3 is a view showing the shapes of a workpiece and part, and FIG. 4is a view for describing processing according to the invention. Theprocessing of the invention will now be described with regard tocreation of NC data for machining a workpiece WK shown in FIG. 3(a) intoa part PT shown in FIG. 3(b).

First, contours CNT1, CNT2 necessary to specify a cutting area AR_(M)[FIG. 4(a)] are inputted using the keyboard 105 or tablet 108, wherebythese contours are displayed on the display screen of the graphicdisplay unit 106 (step 201).

Next, when the menu item "OPTIONAL CUTTING" on the menu table 108b isselected (step 203), a prompt such as "ENTER AREA", which calls for theinput of an area, is displayed on the display screen (step 205).

When the desired area AR_(M) is designated (step 207) by the graphiccursor GCS through use of the tablet cursor 108c in response to theprompt regarding the area, the graphic display unit 106 recognizes thedesignated area and paints the interior of this area in a predeterminedcolor [see FIG. 4(b), step 209].

Next, a prompt regarding tool radius appears on the display screen, inresponse to which a tool radius r is inputted (step 211).

This is followed by selecting a machining starting point P_(s) [FIG.4(c)] by the graphic cursor GCS, whereupon the processor 102 stores thecoordinates of this machining starting point P_(S) in the RAM 103 (step213) and removes the paint in a circle whose center is the machiningstarting point P_(s) and whose radius is the designated tool radius r(step 215). As a result, the operator is capable of perceiving when anarea from which paint has been removed is an area cut.

Thereafter, when the machining end point P_(E) is selected by thegraphic cursor GCS [FIG. 4(d)], the processor 102 stores the coordinatesof the machining end point P_(E) in the RAM 103 (step 217) and causesthe display unit 106 to remove the paint from a linear area AR₁ thewidth whereof is the width of the tool, connecting the machining endpoint P_(E) and the machining starting point P_(S) (step 219). As aresult, the operator recognizes it when the area from which the paint isremoved is cut.

Next, the processor 102 adopts the machining end point P_(E) as the nextmachining end point P_(E) (step 221).

Thereafter, the operations and processing from step 217 onward arerepeated to successively input machining end points [see FIGS. 4(e),(f)] until the last machining end point is entered. When this has beenaccomplished, the operator selects the menu item "END" on the menu table108b [step 223).

When the menu item "END" has been selected, the processor 102 creates NCdata for machining the interior of the area by successively traversingthe machining starting and end points, which have been stored in the RAM103, while the tool is made to move linearly, stores these data in theNC data memory 104 and then ends the processing for creating NC data forthe rough machining of an area.

In a case where excessive cutting would take place by exceeding theboundaries of the designated area AR_(M), the excessively cut portion isrendered distinguishable, as by painting it in a different color. Withsuch an arrangement, excessive cutting becomes obvious at once so that acorrection can be made with facility.

Thus, in accordance with the invention, it is arranged to display, inpainted form, the interior of an area to be machined, successively inputmachining starting and end points and remove the paint in an area cutaway by tool movement along straight lines connecting starting pointsand end points. As a result, it is possible to recognize at a glancewhether portions remain to be cut or will be cut too much, and NC datafor rough machining of an area can be simply created for excellentcutting efficiency.

We claim:
 1. A method of creating NC data for machining any area, characterized by:displaying, on a graphic display screen, contours inputted in order to specify the area; recognizing the area, which is designated by a graphic cursor by manipulation of a tablet, and painting the interior of the area in a predetermined color; removing the paint in a circle having as its center a machining starting point designated by the graphic cursor and as its radius a designated tool radius; then removing paint in a linear area, having a diameter equivalent to a tool width, which connects a machining end point designated by the graphic cursor and said machining starting point, and adopting said machining end point as the next machining starting point; and thereafter inputting machining end points in succession, and creating NC data for machining the interior of the area by traversing a finally designated machining starting point and machining end point while moving a tool linearly.
 2. A method of creating NC data according to claim 1, characterized by displaying an excessively cut portion in a distinguishable manner if cutting is designated that exceeds boundaries of said area. 